Quite a wide variety of safety containers and safety closures for medicine containers and vials are known in the prior art. In addition to the prior art United States patents noted in the above-referenced application, U.S. Pats. Nos. 3,902,620 and 3,989,152 are examples of relevant patented art.
One objective of the present invention is to further improve on the known prior art including the closure toothed locking means shown in the above-referenced application. In accordance with the present invention, a more durable and stable yielding carrier means for the single side mounted laterally movable locking tooth of the container body is provided for improved coaction with a group of widely spaced axially formed teeth on the interior of the skirt portion of the container closure.
Additionally, the present invention provides a unique sealing means on the reversible closure which enables the closure in both of its positions of use on the container to comply fully with the requirements of the classification of "Tightly Closed Containers" under the U.S. Pharmacopeia Standards to become effective in April of 1977. In terms of actual laboratory test results, the invention far exceeds the requirements of the new law relating to moisture permeability. For example, under the new standards, the required National Formulary Test Procedure states "The containers so tested are tight containers if not more than one of the 10 test containers exceeds 100 mg per day per liter in moisture permeability and none exceeds 200 mg per day per liter." The test containers embodying the present invention averaged 77 mg per day per liter with the highest single test vial showing 92 mg per day per liter of moisture permeability.
An important aspect of the invention resulting in the above superior test results is the provision on the reversible closure of a pair of oppositely facing wedge sealing rings which coact cammingly with the mouth of the container or vial in both positions of use of the closure to force the screw-threads of the closure into tight compressive engagement with the opposing threads of the container, and thus form a very positive and effective seal which more than meets the new standards for "Tightly Closed Containers".
Other features of novelty will be apparent during the course of the following description.